Presidential elections were held in Ukraine on 31 October, 21 November and 26 December 2004. The election was the fourth presidential election to take place in Ukraine following independence from the Soviet Union. The last stages of the election were contested between the opposition leader Viktor Yushchenko and incumbent Prime Minister Viktor Yanukovych from the Party of Regions. The election was held in a highly charged political atmosphere, with allegations of media bias, voter intimidation and a poisoning of candidate Yushchenko with dioxin.According to Ukraine's electoral law, a two-round system is used to elect the president in which a candidate must win a majority (50% or more) of all ballots cast. The first round of voting was held on 31 October. As no candidate had 50% or more of the votes cast a run-off ballot between the two-highest polling candidates, Yushchenko and Yanukovych, was held on 21 November. According to official Central Election Commission results announced on 23 November, the run-off election was won by Yanukovych. The election results were challenged by Yushchenko and his supporters, with many international observers claiming that the election was rigged.The subsequent events led to a political crisis in Ukraine, with widespread peaceful protesters, dubbed the "Orange Revolution", calling for a re-run second round election. The Ukrainian Supreme Court annulled the official run-off results and ordered a repeat of second round ballot.The final re-run ballot was held on 26 December. Viktor Yushchenko was declared the winner with 52 percent of the vote to Yanukovych's 44 percent. Western observers reported that the re-run ballot was considered overall fairer than the previous ballots.